[Monstrous4Banger]

Im gonna have to disagree here. Yes, the 16v will ultimately put out more power, especially up top. Everyone who builds 3.0 turbos has told me that. Im aware of the physics. Theyve also all told me that the 8v has more grunt down low, and provides a more broad/seamless powerband. When I think of a car made for the street, I think of seamless boost, and plenty of low end grunt. Could hardly care about top end. Personally. Not like Im ever really going to wrap out 6th gear on the freeway anyway.
Cant get 700hp out of rehashed 951 parts???? I beg to differ. Porsche was pulling 5-600 out of the 2.5 in the early 80's. Their are 2.5's pushing 650+ to the wheels. A 3.0 with a rehashed 8v is capable of much more than 700hp. Kinda pointless tho, in street trim. Over kill is over kill. 700+ in a car designed for about 5-600 max. Your right about no one wanting to make parts for the 16v. Could be more reliable under significant boost, and big power, if it were otherwise. Powerhaus has broken many a 16v. Call Dave and ask him. The 8v isnt only cheaper, actually the 2.7 head(which is OEM) is pretty expensive, but its more reliable for big power. Im not the one who broke them, or was even there when they were broke. Just that my builder, and powerhaus wouldnt lie to me about it. In fact they wouldve profited more by me opting for the 16v. I sourced my own 8v head. C'mon man, the 968 ts <b>is</b> a rehashed 951. Gotta give the 951 its due.
My understanding, based on what people who build 3.0 turbos have told me, and dynos ive seen, and compared. Typically the 8v will put out more tq, under identical boost levels compared to the 16v. Producing a broader band. Under the same boost, where the 16v puts out 400 ft lbs, the 8v sees about 450. In regards to horsepower, the 8v will see less admittedly. The physical reason for this slips my mind at the moment. ill have to get back to you. Once I finally take my 3.0 back on the dyno, Ill be able to show you. Unfortunately, my porsche budget dictates necessities only right now.

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[flash]

post hoc ergo propter hoc

i think you are missing the point i was trying to make - nobody has done a 16v head with the right parts yet - you cannot use the 951 parts on a 16v head and get the power - until very recently, some of the parts did not exist to get the power from a 16v head - they still have not been used on a turbocharged engine, so there is no way for anybody to say that they are getting more from an 8v head than a 16, since they haven't done it with the right parts

but if they did, they would get better and more reliable power from the 16 - when somebody finally does use the right stuff, you'll see the switch

by the way, i was not suggesting that anybody try to get 700hp, but i do know of a few 968 motors that get 650, and want more - pure race cars

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[xrad]

I have to disagree with you Flash, What do you mean "Cheap out??"

I can tell you that with money as no option, I would still do everything as I have done. Trust me, all options have been considered. If you read my topic from the beginning, you will see that this is a build designed for everyone driving a used 'cheaper' 20 year old 968 and one designed for ease of obtaining parts at a reasonable cost and done out of their garage. Even the Darton sleeves have been eliminated in my build due to the now easily available Wossner pistons and rings.
For a car that costs ~13,000 in nice shape, I certainly won't be dumping 30g's into the build to get some awsome numbers on a dyno.

As far as reliability, eight valves all metal lift system with no extra parts (2 cams, chain, tensioner, twice as many valves...all to go bad, etc). Also, the benefits of the ceramic outflow tracts (although size limited) and a head made for turbo..

Sure, physics will determine that flow is greater on the 16valve, BUT WHO REALLY CARES when you are running under 1 atm of boost on the street. I am going to squeeze into each cylinder all the air and fuel I need for this build without killing the engine.

Cheers

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[flash]

i'm not trying to piss anybody off, and certainly i understand that not everybody can afford to go "the whole 9 yards"

to elaborate, to "cheap out" is using inexpensive parts that are less than what you can have in performance or reliability - using used parts rather than new ones is "cheaping out" - i never use used parts on a performance engine - i'd rather make new ones if new ones aren't already available

mickey mousing around a part that should be replaced with a different design is "cheaping out" - i often see people doing things that just make me crazy - it's like going through the whole process, and then not cleaning up the parts around the job, or painting or powdercoating the associated raw metal older parts - i prefer to spend the money and do it right, or not do it at all - these are really inexpensive cars

maybe i'm spoiled - maybe it's just from seeing too many home projects break down - either way the result is the same

if you want a more efficient engine, and certainly a 16 valve engine would be that, you need to use correct parts - many of them didn't exist for the 16 valve engine until just recently, and still have not been used in that application yet - i haven't even heard of anybody trying in a few years now - a lot has been improved on since then - that's why everybody says the 8v works better - they haven't done the 16v right yet

slapping together an engine out of 951 parts might make power, and certainly would be easier, but won't work as well as a properly built 16 valve version - you can't get around the physics - that is why nearly every new car has abandoned the 8 valve design (i think some base model trucks still use it) - but, they created the new parts needed to make it work with more valves

that's all i'm saying - some day somebody will do it, and then we'll all see what could have been - there's nothing technically wrong with doing an 8v, just that a 16v would be better if done right

apples and oranges

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[Monstrous4Banger]

Well, I think it comes down to the intended use of the car. 16v has its advantages, more HP(albeit less torque), and more efficent. Efficiency is the big reason modern cars dont run 8v. The 8v is a more suited powerband for the street. Its all about that curve. Im not saying the 16v isnt capable of more. More flow means more power, in these engines, more power up top. Extra holes, and more flow, and surface area will give you more HP, once the pressure buids up. Less holes, and just small enough internals builds pressure quicker, putting more tq out down low. More hp sounds like a nice track car to me. 8v is more instantaneous, cause it builds the pressure quicker. Fizzles out up top, in the HP band, cause it doesnt have the flow, that extra surface area. Very much apples, and oranges.

"to elaborate, to "cheap out" is using inexpensive parts that are less than what you can have in performance or reliability - using used parts rather than new ones is "cheaping out" - i never use used parts on a performance engine - i'd rather make new ones if new ones aren't already available

mickey mousing around a part that should be replaced with a different design is "cheaping out" - i often see people doing things that just make me crazy - it's like going through the whole process, and then not cleaning up the parts around the job, or painting or powdercoating the associated raw metal older parts - i prefer to spend the money and do it right, or not do it at all - these are really inexpensive cars" -Flash

Youve never used used parts on a performance engine? So, you would fabricate your own cylinder head? Last I checked Porsche didnt sell the heads any more. That leaves one option, buying used, and rebuilding. Where can you find a brand new 16v? Just because I cut out the middle man doesnt mean I cheaped out on anything. It really wouldnt have been much more to use the 16v. I chose not to for specific reasons.
Mickey mousing around? What part should be replaced? All my parts were fully rebuilt, like new. "Doing it right" in this situation will depend on what your using the car for, and how you utilize the power. Painting, and powdercoating? Meh, like my shovelhead ridin, biker step father told me when I was very young, "chrome dont get ya home". I leave things stock looking as much as possible. That dont mean it aint clean tho. Well, my valve cover is polished. [img]style_emoticons/<#EMO_DIR#>/tongue.gif[/img] BTW Flash, your not pissing me off at all. I agree with some of what your saying. I just think your underestimating the 944/51, and the 924/31, and the role they played in the 968's pedigree. If a 8v 3.0 turbo is mickey mousing around, then porsche should be called disney. Im following their lead. They chose the 8v on the 968 TS for a reason. They couldve easily put a 16v on the TS, and the TRS......Why did they ditch it for an 8v as soon as they put a turbo on?

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[flash]

set up properly, a 16 valve design is a better design for power, reliability and efficiency - it develops more torque lower in the band too, as a function of more flow - the only reason that people have had a different experience with the 8 valve on this car is that nobody has done the 16 valve right yet - once they do, you will see that the 16 valve will outperform the 8 valve in every respect (except maybe cost)

porsche used the 8 valve head on the turbo for one reason and one reason only - cost - the same reason other do - they did not want to cast the intake manifold needed to make the 16 valve head work properly - it would have cost a couple of million dollars to tool up and test for street applicability - with the US refusing to allow the car in, there was no motivation - they were able to accomplish their goals by reusing the 951 parts - if that car ever got to production, it would have been 16 valve - i have a memo around here somewhere that lays out the initial plans for that engine, including a bore out to up to 3.4 liters

chrome may not get you home, but powdercoating and paint help in cooling, and facilitate the ease of cleaning, which continue to help in cooling

as for me using used parts like heads and such, actually i usually bought a new one to use as a core for the race cars - even this last go around i was reluctant to re-use a head, and almost bought a new one - the only reason i didn't was the time factor, as i am trying to get the project out the door - when it comes back out, it gets a new one - when i build the race car, it gets a new one

but we are now getting WAY off track of xrad's initial thread, which was about his build, and i have to apologize for being a part of that - what i would do has absolutely nothing to do with what xrad is doing - i was responding to monstrous' post, and completely lost sight of the origination of the thread - we can start an entirely new thread to discuss the merits of 8 valve vs 16 valve if you like

we now return you to your regularly scheduled programming

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[xrad]

THANKS, Flash! I am glad you realized the side tracking. As well all know, most of us on this website drive a used 20 year old sports car called a 968(NOT expensive as used sports cars go) into which they will not likely dump a ton of cash for a build project.

and by the way, the whole car is made of old parts ...if it is in spec, who cares??

This build is therefore for everyone else ......

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[flash]

lol - we digressed again, so i removed the last 6 posts, which were not about xrad's build - please start a new thread to discuss new vs rebuilt so we can keep this one on track for xrad

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[Seven30]

While waiting for Xrad's next post:

Flash - could you please spend a few minutes to sum up what parts that "haven't been made yet" for that successful boosted 16V build, maybe starting a new tread if it ruins this one?

Also, I think it was monstrousfourbanger that wrote about oil cooling challenges of the valves for the 968 N/A head: Could you please elaborate?

Just trying to learn from you both [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

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[flash]

at the extreme risk of sounding jaded, and not wanting to belabor the subject, since nobody is going to do this, hence it's moot, you could start with the intake manifold, and all of the plumbing - none of the existing stuff will work well with the 16 valve 968 head - that's why those who have tried have failed to get good results - making the stuff that would work would require a LOT of time and money - in the end, it would be better, but since most of the guys doing these things rubber band and bubble gum together stuff they get on ebay, and work with very small budgets, and none of them do what is really needed for tuning, this route will likely never be pursued

but, pop on by for the ortega run on the 11th and we can discuss this more in detail

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[333pg333]

Intake / ITBs, Electric water pump/s, deckplate, Larger diameter headstuds, totally custom crank, cam/s, pistons, rods, dry sump, maybe water to air i/c, sequential CDI, Standalone of course.
Just to name a few items...

The 16v is also a lot more resistant to knock and of course it flows a lot better than even the best custom worked 8v heads. All this talk about 16v having less torque and all the power moved way to the right is poor theory. As Flash says, very few people have done a proper 16v build right. Not a lot of really decent 8v builds for that matter. What high torque motors nowdays only have 2v per cylinder?

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[Monstrous4Banger]

Obviously if you work the 16v, it is capable of more. The dynos speak for themselves tho, powerhaus has probably compared more than anyone. If its about how far you can push the envelope modding them, the 16v is the obvious choice.

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[xrad]

Hi everyone!!! THANKS FLASH for fixing my security key...I could not post for months.



Anyway, glad to see this thread is still alive and well. The build has been on hold as I enjoyed the car through the summer as is. Running flawlessly. every part and switch functions like the day it was assembled.



I appreciate all the input. However, this conversion will be on hold as I try to complete my other fun ride Alfa GTV6. transaxle work. almost new 3.0. body shop with one of a kind details..etc...



some pics (yes, I know, not a 968..but it;'s my thread...no more Alfa after this)



so hopefully next summer, start on turbo build



Cheers

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[flash]

lol - i did nothing - it was something on your end - emails i sent you bounced back too



but welcome back

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[duke]

[quote name='flash' timestamp='1283553520' post='97982']

at the extreme risk of sounding jaded, and not wanting to belabor the subject, since nobody is going to do this, hence it's moot, you could start with the intake manifold, and all of the plumbing - none of the existing stuff will work well with the 16 valve 968 head - that's why those who have tried have failed to get good results - making the stuff that would work would require a LOT of time and money - in the end, it would be better, but since most of the guys doing these things rubber band and bubble gum together stuff they get on ebay, and work with very small budgets, and none of them do what is really needed for tuning, this route will likely never be pursued



but, pop on by for the ortega run on the 11th and we can discuss this more in detail

[/quote]



What's the reason you say "those who have tried have failed to get good results" regarding 16v turbo?

Everyone has their own definition of "good results" but if you don't know every 16v turbo build done worldwide you might want to be a tad more humble than stating "nobody has done it", "everyone has failed" etc. There might actually be great stuff done without you knowing it.



A 16v turbo is superior in most ways and you don't need to re-invent the wheel to make it work. A competent race engine shop that knows turbocharging can do it. IMHO it is a huge disadvatange for the 944/968 community that so many people continues to state how difficult it is to build a 16v turbo. And 99% of those who state that haven't even tried.

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[flash]

it's not a case of not being humble - it' a case of countless stories of failed attempts



i don't have to actually climb mount everest to know how hard it is - some things are just known from those who have tried



if one had been done, somebody here would almost certainly know about it - i've been scouring the internet for 7 years now for information on these cars, and others here have as well - it is extremely rare for one of us to find something new, and a successful16V turbo would be big news that not too many would keep secret - i suppose it's possible, but not terribly likely that somebody has one



again, i'm not saying it can't be done, or that it wouldn't be better - it can and it would - but rather all i am saying is that nobody has gone to the expense of making it happen



there is one car that i still have to check out that may have pulled it off, but at great expense, and output is well under the 400hp mark that so many seek

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[duke]

Flash, I see your point. I think my engine would qualify as a successful 16v project. I see Patrick mentioned it in another thread, I will post some info about the engine there.

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[xrad]

nice to see this thread is still alive and kicking!



Anyway, turbo project cancelled for now as I bought another Alfa to go with the one above (red this time). I have listed the parts for the turbo conversion in the for sale section if anyone interested.



Unfortunately, too many projects at this time. I don't need to sell the parts, but if anyone is interested, they are for sale. I included an email in the for sale section.



look here:

http://www.968forums.com/topic/10790-sal...ion-parts/



PS: I am keeping the 968 a she runs like a champ and of course fun to drive!



Nice to read through the forum again!

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[xrad]

Oh My GoD! I just read through this whole thread and realized it's been 2 years since I did anything ..sheesh! where is time going!! <img src="/forum/images/smilies/968/blink.gif" class="smilie" alt="" />



Sorry for the delay to everyone who was following this build!

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[xrad]

Hi everyone....Got the 968 out of storage. been a while and not nice...puddle of antifreeze under car. OOOOPs..that is new . and the heat stayed on even on cool settings.



Anyway, tracked it down to the heater valve..diaphram and valve both shot....easy fix with my new standard metal spare...normally, I would have clocked all the clamps to face the same way...but I was in a rush. kinda tight down in there, but easy to do with power steering reservoir and oil filter out of the way.





Oh, and I rebuilt another car in the meantime..Alfetta 2.0, 1978 red beauty. almost all done...

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